Growers need as much in-the-field information as possible to find ways to manage BMSBs. “Monitoring tools are used to assess the presence, abundance, and seasonal activity of pests and natural enemies to determine the need for and timing of insecticide applications,” says Leskey.

“Specifically, our group evaluated responses of brown marmorated stink bugs using different visual stimuli, compared the effectiveness of commercially available traps from Asia with a black pyramid prototype trap, compared relative attraction to different doses of odor attractants, and conducted a field cage experiment designed to establish how often the brown marmorated stink bugs reproduce.”

Leskey has focused on visual stimuli that can, in addition to odor stimuli, attract the BMSBs to traps that will help farmers monitor the level of infestation in fields.

“We used pyramid-shaped traps of different colors — black, green, yellow, clear, white. In field trials in 2009 and 2010, we found significantly more stink bug adults and nymphs captured in the baited black pyramid traps than in the other traps,” says Leskey.

“Further, more adults and nymphs were captured in a trap placed on the ground than in a commercially available baited trap from Japan that we hung from a tree limb.”

“We also found that in 2010 and 2011, brown marmorated stink bugs produced two generations in 1 year in Kearneysville, based on presence of eggs and newly molted adults in field cage experiments,” says Leskey. “Although it has been reported that these bugs produce only one brood in eastern Pennsylvania, it appears that in more southerly locations within the Mid-Atlantic, they can produce two generations.”

Secrets of attraction

Researchers at the ARS Invasive Insect Biocontrol and Behavior Laboratory (IIBBL) in Beltsville, Maryland, are leading the pivotal pheromone research efforts and genomics studies and partnering with Leskey on field tests of potential attractants for use in commercial traps.

Scientists at IIBBL were working on the BMSB long before it became such a huge problem in the United States.

Aijun Zhang, an analytical chemist, started looking for the BMSB pheromone in 2003, along with Ashot Khrimian, a synthetic chemist, and Jeff Aldrich, an entomologist who retired in 2011.

Khrimian and Aldrich published results in the Journal of Agricultural and Food Chemistry and in Tetrahedron, showing that a compound identified as a pheromone of another stink bug was also a late-season attractant for the BMSB. When the BMSB emerged as a major pest in the United States, Aldrich and Khrimian began helping U.S. manufacturers develop traps with the attractant.

“Our work has already led to successful commercial products now on the market. But what we now have is only a late-season attractant, and because that doesn’t help growers as much as we would like, we still have work to do,” Khrimian says.